Automatic headlight control



May 6, 1941.

WITNESS 2 g .L. W. GILLESPIE AUTOMATIC HEADLIGHT CONTROL Filed Nov". 10, 1958 2 Sheets-Sheet 1 bzverzior Leonard 14 QY/espie, Deceased, fly, 1/0/10 M Parker, Adm/h/lsfrafon ATTORNEYS May 6, 1941. L. w. GILLESPIE 2,240,843 AUTOMATIC HEADLIGHT CONTROL Filed Nov. 10, 1938 2 Sheets-Sheet 2 5/50 PHOTO CELL 43 nmmmlmm CONTROLLED 6a RELAY Leonard 14 5/7/96 1/"6 Dec'eaded, By Jo/m fiPar/fer; fldmillisfr'afor.

"TNESS I ATTORNEYS Patented May 6, 1941 'UNITED STATES PATENT'OFFICEY 2,z4o,s4s AUTOMATIC HEADLIGHT CONTROL Leonard W. Gillespie, Greensburg, Iml.

Application November 10, 1938, Serial No. 239,896

' 4 Claims. (c1. 171-97) The object of the invention is to provide means for. application to motor vehicles to function in established; and to provide an automatic headlight control which is of comparatively simple form and susceptible of cheap manufacture and installation on conventional motor vehicles without modification thereof.

With this object in view, the invention consists in a construction and combination of parts of which a preferred embodiment is illustrated in the accompanying drawings but to which the inventlon is not to be restricted. Practical application may dictate certain changes or alterations and the right is claimed to make any which fall within the spirit of the invention. V

In the drawings:

Figure 1 is an elevational view showing the forward ends of approaching automobiles with the invention applied in operative position.

Figure 2 i a vertical sectional view through the control light casing.

Figure 3 is a front elevational view of the structure of Figure 2.

Figure 4 is a diagrammatic view.

The invention comprises a light sensitive cell III which is afiected by the headlight of an appreaching vehicle, or by an auxiliary light, and controls means by which the headlight' of the associated vehicle, if in the bright position, will be shifted over to the dim position. The light sensitive cell I is mounted in a casing l I carried on an appropriate bracket l2 which is attached to the vehicle l3 directly below the headlight M.

which lead to the relay 2| are connected with them.

Mounted in the front wall of the casing II is a flaring lens tube 22 at the outer end of which is'carried a converging lens 23 and a visor 24.

Directly below the lens tube but mounted on the front wall of the casing II is the auxiliary energizing light casing 25 provided with a lens 26. Within the lens casing is the light 21 which is carried in the socket 28, the light being fed through the conductors 29, of which one, as indicated at 29a, is grounded, preferably to, the case, if the ground be not made within the socket itself. The casing 25 and its lens 26 are of oval horizontally.

Mounted within the casing II is the supplemental light 30 which is carried in the socket 3| supported on a bracket 32 on the inner face of the front wall of the casing ll, conductors 33 feeding the light 30 but one, as at 33a, being grounded. The conductors 33, 29 and 20 are preferably incorporated in one cable which is led to the relay 2 l the relay being preferably mount ed interior to the vehicle. The bottom wall of the casing II is bushed, as indicated at 34, where the cable passes through the wall of the casing, the bushing being preferably an insulating bushing.

The relay indicated at H is the conventional photo cell controlled relay consisting of one or more triodes of which the grid circuit of the first,

7 say, isconnected wit-hthe light sensitive cell i0,

The casing II is in the form, preferably, of a rectangular parallelopiped and is split on a diagonal line to provide the sections Ila and lib, each of which is flanged, as indicated at 15, the sections of the casing being secured together by hand screws l6 passing through body holes in s one of the conductors 20 being connected with the grid and the other with the cathode of the tube.

The filament circuits of the tubes are energized from the car battery 35, grounded, as in the conventional practice, at 36, with the positive pole connected by means of a conductor 31 with the armature 38 and with the relay 2|, by means of a conductor 39 at the binding post 40. A main line-switch 4| is interposed in the conductor 31 and a similar switch 42 in the conductor 39. A relay 43 controlling a telltale lamp 43a is also connected serially in the conductor 39. The relay 2| is grounded at the binding post 44, as indicated at 45.

Plate current for the relayis obtained either from the generator end 46, of the motor generator set 46-41, or from an alternating current generating device 48 energized from the battery 35, the triple-pole double-throw switch 49 connecting in the motor generator set or the generating device 48.

a relay in the plate'circuit ot the triode in the relay 2|. It is normally spring impelled away irom the contact but engages'the latter conta'ct when the magnet, 50 is energized.

It desired means may be provided for looking it in its retracted position.

The headlight shown i or the dual filament I form and either the brightor the dim filament is tion, are approaching each other and let it be assumed that the first eflect is the result or the rays oi the headlight of the car l3a. These will I pass through the condensing lens 23 and energize the cell Ill whose resistance, being thus lowered, affects the grids in the triodes in the connected in circuit by the appropriate setting oi the manual switch 52.

The alternating current generating device 48 2 comprises a transformer '53 across whose secondary is connected a condenser 54 but whose primary is center-tapped and grounded through a conductor 55 in which is'interposed a resistor 55 by-passed on either side by condensers 51 connected with the ground. A resistor 58 prelerably bridges the entire primary. The extremities of the primary are connected with contacts 59 and 50 respectively between which vibrates an armature 5|, the armature being spring impelled toward a contact 52 in series with a magnet 53 which -is connected with one extremity of the primary.

When the switch 49 is in the position to connect the generating device 48 in circuit, current fiows from the battery 35 over theconductors 31 and 39 (the switches 4| and." being closed), through the relay 43, the conductor 54,. to the hinge clip of one of the blades'of the switch 49-,

thence over the connected switch blad'eto the forked clip of the switch, thence over the conductor 55 to the armature 6| which is in engagement with the contacts 58 and "by reason of the pull of the spring 55. From the contact 52,

current flows through one side of theprimaryot the transformer and thence over-theconductor-55 to the ground. A second increment of the currelay 2|, so that current will flow in the plate circuits or the triodes and eflect energizatlon oi. the relay which controls the circuit of the magnet 50, so that the circuit of such magnet is closed. The armature 38 wfll then be drawn into engagement with the contact 5| and battery current will flow over the conductor 31, the armature 38, the contact 5|, the conductor III, the filament D and then through the ground back to the battery, it being assumed that the switch 52 was inthe position to place the B filament in circuit. But an increment oi the current that flows over the conductor 31 will also flow over the conductor 1|, through the winding of the thermostat 69 to the ground and thence back to the battery. Likewise an increment will flow over one of the conductors 33, through the lamp 30 and back to the battery through the ground connection.

. The light 3|! is provided to give the additional luminosity necessary to keep the cell Ill active if the headlight on the car |3a has been dimmed, the dim filament of the car- |3a together with the light 21 thereof providing jointly with the lamp 30 of the car l3 a sufficient luminosity to keep the cell Inactive. Asv long as the light But the current flowing through'the winding of the thermostat 69 will, after an interval, be sufll.

, cient to-fiex the thermostat, so that it will open rent flows through the opposite side of the pri mary of the t'ransformer'and'thence'xoverthe conductor 55 to the ground. 5 But current pa'ssing from the contact 52 passes through the magnet 53, so that the armaturelil is raised and disengaged from the contacts 58 and 52 but en- 7 I gaged with the contacts 50, when batteryjcurrent will flow'from the armature over the contact 50 through the ground connection in all cases. The

"current flowing. v b

. If,'for example, the headlight l4 of the car I3 is the circuit'on the light2l. 'I'helightwill thus be put out as will the correspondinglight on the car 13a by the functioning 0f itsthermostat. This will leave only thelightsj 30 as the. activating means for the-cell I0 which will be insufilcient to maintain any grid condition of the triodes in the relay 2| that'will permit of any material plate dimmed by the-light on the car 13a affecting the i-. cell H) on the car 13, the series of operations continual making-andbreaking oi'the primary circuit results in the well known changing mag- 'netic field which reacts on thesecondary or the transformer. The extremities of the secondary with the two remainingiorked clips on the one side of the double-throw triple-pole switch 49 so that plate current will flow over the switch blades through the conductors to the plate circuits of the triodes in the relay 2|. I

When the motor generator set is employed for plate energization in the relay 2|, the switch 49 is thrown to connect that in circuit, when battery current will flow over the conductor 54 and.

through the motor 41 and back to the battery are connected by means of the conductors -51 over the ground connections. The generator output will then flow over the conductors 53 to the plate circuits of the triodes.

described above will 'take place onthe car l3. But then thereare'no bright headlight rays to afiectthe cell H) on the car |3a. i On' the automatic switching-tothe-D filament' oithe car l3,

-"-however, the-light 21 of the'car I3 is placed in 55" the car l3a. The lights 21 only function in the circuit and energizes the-light sensitive cell In in switch-over to the D filament in-the headlight.

When the magnet 50 is not energized, the armature is engaged with a contact 12 which is connected by means of a conductor 13 with the blade of the switch 52 which is of the single-pole.

"claimed as new and useful is:

I 1. An automatic headlight control for motor vehicles comprising, in combination with a vehicle headlight having bright and dim filaments, a switch normally in the position to excite the bright filament but shiItable to deenergize the latter and excite the dim filament, automatic means controlling said switch, a. light sensitive cell controlling said automatic means and positioned for energization by the headlight of an approaching vehicle, a supplemental light positioned adjacent said cell and energized in the dim position of said switch, and an auxiliary energizing light energized when the switch is in a dimmed position and so positioned to affect the cell of an approaching car on which the corresponding auxiliary energizing light jointly with the supplemental light maintains the activity of said cell.

2. An automatic headlight control for motor vehicles comprising, in combination with a vehicle headlight having bright and dim filaments, a switch normally in the position to excite the bright filament but shiftable to deenergize the latter and excite the dim filament, automatic means controlling said switch, a light sensitive cell controlling said automatic means and positioned for energization by the headlight of an approaching vehicle, a supplemental light positioned adjacent said cell and energized in the dim position of said switch, and an auxiliary energizing light energized when the switch is in a dimmed position and so positioned to aflect the cell of an approaching car on which the corresponding auxiliary energizing light jointly with the supplemental light maintains the activity of said cell, the said auxiliary energizing light being provided with an automatic delayed cutout.

3.'An automatic headlight control for motor vehicles comprising, in combination witha vehicle headlight having bright anddim filaments, a switch normally in the position to excite the bright filament but shiftable to deenergize the latter and excite'the dim filament, automatic means controlling said switch, a light sensitive cell controlling said automatic means and positioned for energization by the headlight of an approaching vehicle, a supplemental light positioned adjacent said cell and energized in the dim position of said switch, and an auxiliary energizing light energized when the switch is in a dimmed position and so positioned to afiect the cell of an approaching car on which the corresponding auxiliary energizing light jointly with the supplemental light maintains the activity of said cell, the cell and supplemental light being housed in a casing positioned below said headlight and the casing having a condensing means carried in the front wall thereof to concentrate the light rays from an approaching vehicle on said cell.

4. An automatic headlight control for motor vehicles comprising, in combination with a vehicle headlight having bright and dim filaments, a switch normally in the position to excite the bright filament but shiftable to deenergize the latter and excite the dim filament, automatic means controlling said-switch, a light sensitive cell controlling said automatic means and positioned for energization by the headlight of an approaching vehicle, a supplemental light positioned adjacent said cell and energized in the dim position of said switch, and'an auxiliary energizing light energized when the switch is in a dimmed position and so positioned to affect the cell of an approaching car on which the corresponding auxiliary energizing light jointly with the supplemental light maintains the activity of said cell, the cell and supplemental light being housed in a casing positioned below said headlight and the casing having a condensing means carried in the front wall thereof to concentrate the light rays from an approaching vehicle on said cell, and the auxiliary energizing light being carried by said casing and disposed below said condensing means, and a casing enclosing said energizing light and being provided with an oval lens closing the front thereof, the major axis of the oval being horizontally disposed.

LEONARD W. GILLESPIE. 

